Advertising and Marketing

The Importance of a Strong Book Cover: A Case Study

By: D.F. Hart on January 8, 2021

Our Hidden Gems guest author for today.

By: D.F. Hart on January 8, 2021


We’ve published numerous blogs touting the importance of your cover when it comes to selling your book, but it’s often hard to give a concrete apples-to-apples example because the cover is rarely the only difference between two books. That is, if we looked at the great sales of Book A (with a strong cover) compared to the lower sales of Book B (with a weak cover), it would be impossible to argue that the cover was the sole defining factor. Maybe Book A also had a better blurb, or was written by an author with a stronger following, or was in a more popular genre or sub-genre. Any number of factors could be the cause.  So when D.F. Hart told me of her recent surge in sales after simply changing the covers on an existing series, I knew it was something that our author community would want to hear about. It’s so rare that we get the opportunity to see hard data that backs up the theory of how important a strong book cover is in such a compelling example as this one, and I’m so grateful that D.F. agreed to share her results with us.


There’s so much that goes into producing a book that people want to read. You spend hours upon hours crafting each word, each nuance, and at least you reach the end of your tale.

Now what? How to take that wonderful creation and build a ‘perfect storm’ that lures readers in and makes them lifelong fans of yours?

Well, conventional wisdom (and market research) makes certain things very clear, among them being this: You really need a book cover that hits genre expectations and pulls your potential audience in. After all, it’s the very first thing a potential reader sees.

The following is my own path on this indie author journey and what I experienced when I finally stopped being in denial and realized that my existing covers, while pretty, were completely missing the mark.

Here’s what happened in my case. First, a bit of background.

I write in two genres (Mystery/Thriller and Contemporary Romance) and began self-publishing in March of 2019. And I will be the first one to admit I had ZERO CLUE what I was doing. No marketing skills, not even any sort of newsletter following. NADA.

I started with Kindle Unlimited, and quickly realized that for my writing style the ‘rapid release’ model was unsustainable. So after roughly six months exclusive to KU, I opted to make a major change and moved my existing works wide. But even then, even as I learned and grew and finally got my act together along about book three of my thriller series and started doing things like actually building a subscriber following, things still weren’t taking off the way I’d hoped.

My total revenue for 2019 came in at just under $600 – and I’d spent more than that just on covers. Tack on editing and marketing spend, and well, you get the idea.

2020 came along, and I did have more of my act together – booking promos, applying for (and being rejected for) that Holy Grail of advertising, a Book Bub Featured Deal (BBFD), every 30 days like clockwork, making book one in my thriller series permafree as part of a more thought-out marketing strategy, and so on.

But by mid-September 2020, frustrated with sales revenue that creeped along at roughly the prior year’s numbers, I booked a consult with Craig at Hidden Gems, because I knew something was wrong with my current setup, I just didn’t know what.

Initially, my intent was for Craig and I to focus on solely the contemporary romance novella series that I’d started in the spring and that I was struggling with.

Imagine my shock when he mentioned, “Let’s look at your thriller series while we’re talking.”

“Why?” I asked, reluctant to change anything about that body of work.

“That series has been out longer, right? More data?”

“Yep,” I said.

“Just trust me,” Craig replied. “Let’s take a look at it.”

And the first thing he said to me when we drilled down into it all was “It’s your covers. They don’t ‘say’ thriller series. That’s your problem.

Now, I admit, when I first heard that I was resistant – partially because I’d allocated cover budget toward trying to get the romance series off on a better foot, and partially because I can, at times, be very mule-headed.

But once I took a step back and thought about it, I realized he was right.

My current designer’s covers weren’t horrible, but they definitely weren’t portraying the mystery/suspense/thriller genre I was writing in. The majority of the people I was writing my stories for were passing them by based on the covers not being right.

I took a deep breath, ran some numbers, and made the decision to get the thriller covers right. At that point in time, I felt like it was do or die, so, I stopped all extraneous spend, including ads, and focused on the series covers.

After a few days of deep research in my genres, I selected a different designer whose focus is more mystery/thriller and let him do his thing.

The top row shown here are the pretty but not ‘dialed in’ original covers, and the bottom row are the new covers:

Cover comparisons

October 10, 2020 is the day that I uploaded all the new book covers.

Then, I opted to do some testing.

I’d run paid promos in late April / May and in late August / early September with the old covers. Those results looked like this. The best month I had was 167 units moved (paid and free).

Old book cover data

I booked those same paid promos again in late October / early November, once the book covers were updated across all retailers. Here’s how those results look – I topped out at 7,587 units moved (paid and free).

New book cover data

And remember when I said I’d been applying religiously for a BBFD on my first in series and gotten rejections every month of 2019 and 2020?

Thanks to the new cover on my permafree book one, I finally landed that coveted – and worldwide – BBFD.

It ran December 14th, and it exploded my visibility – and sales revenue. Here’s how December 2020 has looked for my thriller series in terms of units moved (paid and free):

BBFD data

Lastly, remember when I said I only made $600 for all of 2019?

I made more than that just from 10/10 – 12/13 – BEFORE my BBFD even happened.

And I believe 1000% that it’s because my book covers now scream “Hey I’m an awesome thriller, read me!”

But the icing on the cake has been landing that BBFD. I truly believe if I had kept the old covers in place, I’d still be applying – and still be getting turned down.

December 2020 is my first four-figure month EVER as an author, and I am optimistic that it will not be my last. I’m on pace to at least quadruple my royalty revenue in 2020 comparative to 2019. Because I optimized my covers and let them finally be the genre-specific marketing beacons – the awesome leading edge of my books’ ‘perfect storm’ – that they are supposed to be.

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About the Author

Our Hidden Gems guest author for today.

D.F. Hart resides in Texas. She loves to write and to read when she's not putting her MBA with Accounting concentration to use. Her favorite authors include Frederick Forsyth, Ken Follet, and J.D. Robb. Other interests include hidden object and puzzle games -she loves a good mystery storyline! She writes as Faith Hart for her "Another Try" contemporary romance novellas, and D.F. Hart for her thriller series "Vital Secrets". All of her books are available across all retailers. To learn more about her works, visit her website or follow D.F. Hart or Faith Hart on Bookbub.

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  • Pingback: 5 Critical Elements of Indie Book Cover Design  - Independent Book Review
  • You, my dear, kick ass. I’m so proud to see how far you’ve come and how far I believe you’ll go. Thanks for taking the time to write this up!